Upper Respiratory Infection ('Cat Flu')

Also called: URI, cat flu, feline respiratory disease complex

• Cats
• Respiratory
• Any (esp. kittens)

'Cat flu' is a common, highly contagious infection of the nose, throat, and eyes, most often caused by feline herpesvirus and feline calicivirus, and sometimes bacteria. It spreads easily between cats, especially in shelters and multi-cat homes. Many cats recover in a week or two, but herpesvirus stays in the body for life and can flare up during stress.

Signs to look for

• Sneezing
• Runny nose and discharge from the eyes
• Conjunctivitis (red, swollen eyes)
• Mouth ulcers (especially with calicivirus), drooling
• Lethargy and reduced appetite
• Fever

How a vet diagnoses it

Usually a clinical diagnosis based on signs and history. PCR testing of swabs can identify the specific virus or bacterium when needed (e.g. in catteries or shelters).

Treatment

Mostly supportive — fluids, nutritional support, keeping the nose and eyes clean, and a quiet warm environment. Antibiotics target secondary bacterial infection; eye and anti-viral medications are used in some cases. Vaccination (part of the core F3 vaccine in Australia) reduces severity and spread.

Monitoring at home

For chronic herpesvirus carriers — frequency of flare-ups, eye health, and stress triggers; appetite and hydration during acute episodes.

Who tends to get it

Kittens, unvaccinated cats, and cats in shelters or multi-cat/breeding environments are at highest risk. Herpesvirus carriers may have recurrent bouts lifelong.

Sources

• Cornell Feline Health Center — Respiratory Infections
• RSPCA Australia — cat vaccination